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931.
Casalderrey M Souto C Concheiro A Gómez-Amoza JL Martínez-Pacheco R 《Chemical & pharmaceutical bulletin》2000,48(4):458-463
Three processed lactose-cellulose blends of similar composition, particle size and true density were compared as direct compression excipients: one was prepared by dry granulation, one by extrusion-spheronization, and the commercial product Cellactose. Differences among their flow properties depended solely on their different sphericities. Unlike those of the other blends, Cellactose particles exhibited numerous macropores. The mean yield pressures of all three blends were similar to those of direct compression lactoses. Cellactose tablets prepared at a punch pressure that largely eliminated macropores (pores >1 microm) had better mechanical properties but much poorer disintegration than tablets of the other blends prepared at the same punch pressure. However, the tensile strength and disintegration time of Cellactose tablets both fell rapidly as macropore volume was increased by reducing punch pressure, while the enthalpy of wetting/dissolution rose. The strength and water-resistance of well-compacted Cellactose tablets is attributed to the spatial distribution of lactose and cellulose in Cellactose particles, rather than to beta-lactose content or extra-particular structural features. 相似文献
932.
Miguel Clemente-León Eugenio Coronado Carlos J. Gómez-García Eugenia Martínez-Ferrero 《Journal of Cluster Science》2002,13(3):381-407
The use of polyoxometalates (pOM's) as inorganic component in the synthesis of new molecular hybrid materials is presented. Here we show that the combination of organic molecules of the tetrathiafulvalene (TTF) type or perylene (per) with POM's yields new radical salts with unprecedented structures that present interesting magnetic and/or electrical properties or coexistence of both. The first true metallic radical salt containing a POM has been prepared and characterized. We also describe the recent results obtained by combining magnetic POM's with the organometallic cation decamethylferrocene. 相似文献
933.
Chakraborty D Horchler S Krätzner R Varkey SP Pinkas J Roesky HW Usón I Noltemeyer M Schmidt HG 《Inorganic chemistry》2001,40(11):2620-2624
Reaction of t-BuP(O)(OSiMe(3))(OH) with Me(3)Al leads to the formation of [Me(2)Al(mu-O)(2)P(OSiMe(3))(t-Bu)](2) (1) whereas Me(2)AlCl reacts with Ph(2)P(O)(OH) to yield [(Cl)(Me)Al(mu-O)(2)PPh(2)](2) (2). These compounds represent the first examples of functionalized dimeric four-ring type aluminophosphonate systems. The double four-ring type gallophosphonate, namely, [t-BuPO(3)GaMe](4), reacts with n-Bu(4)NHF(2) under ambient conditions, resulting in the formation of a monomeric gallophosphonate [n-Bu(4)N][MeGa[t-BuPO(2)(OH)](3)] (3). These derivatives have been adequately characterized using various spectroscopic techniques and X-ray diffraction studies. 相似文献
934.
Arelí Durón-Castellanos Vanesa Zazueta-Novoa Hortencia Silva-Jiménez Yolanda Alvarado-Caudillo Eduardo Peña Cabrera Roberto Zazueta-Sandoval 《Applied biochemistry and biotechnology》2005,121(1-3):279-288
Different soluble NAD+-dependent alcohol dehydrogenase (ADH) isozymes were detected in cell-free homogenates from aerobically grown mycelia of YR-1
strain of Mucor circinelloides isolated from petroleumcontaminated soil samples. Depending on the carbon source present in the growth media, multiple NAD+-dependent ADHs were detected when hexadecane or decane was used as the sole carbon source in the culture media. ADH activities
from aerobically or anaerobically grown mycelium or yeast cells, respectively, were detected when growth medium with glucose
added was the sole carbon source; the enzyme activity exhibited optimum pH for the oxidation of different alcohols (methanol,
ethanol, and hexadecanol) similar to that of the corresponding aldehyde (≈7.0). Zymogram analysis conducted with partially
purified fractions of extracts from aerobic mycelium or anaerobic yeast cells of the YR-1 strain grown in glucose as the sole
carbon source indicated the presence of a single NAD+-dependent ADH enzyme in each case, and the activity level was higher in the yeast cells. ADH enzyme from mycelium grown in
different carbon sources showed high activity using ethanol as substrate, although higher activity was displayed when the
cells were grown in hexadecane as the sole carbon source. Zymogram analysis with these extracts showed that this particular
strain of M. circinelloides has four different isozymes with ADH activity and, interestingly, one of them, ADH4, was identified also as phenanthrene-diol-dehydrogenase,
an enzyme that possibly participates in the aromatic hydrocarbon biodegradation pathway. 相似文献
935.
A. Villares S. Rodríguez C. Lafuente F. M. Royo M. C. López 《Journal of solution chemistry》2004,33(9):1119-1133
Experimental viscosities and the corresponding viscosity deviations for the binary mixtures of a cyclic ether (tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran, or 2,5-dimethyltetrahydrofuran) with benzene, toluene, fluorobenzene, or chlorobenzene are given at 25°C. The kinematic viscosities and the corresponding densities were measured with an uncertainty of ±10– 4 mm2-s– 1 and ±(5×10– 3) kg-m– 3, respectively. The viscosity data were correlated by the equations of Grunberg–Nissan, McAllister, and Heric. On the other hand, the results have been compared to the predictions, by the method proposed by Asfour. 相似文献
936.
Identification of aroma active compounds in orange essence oil using gas chromatography-olfactometry and gas chromatography-mass spectrometry 总被引:3,自引:0,他引:3
Using GC-MS and GC-flame ionization detection (FID)/olfactometry, 95 volatile components were detected in orange essence oil, of which 55 were aroma active. In terms of FID peak area the most abundant compounds were: limonene, 94.5%; myrcene, 1%; valencene, 0.8%; linalool, 0.7%, and octanal, decanal, and ethyl butyrate, 0.3% each. One hundred percent of the aroma activity was generated by slightly more than 4% of the total volatiles. The most intense aromas were produced by octanal, wine lactone, linalool, decanal, beta-ionone, citronellal, and beta-sinensal. Potent aroma components reported for the first time in orange essence oil include: E-2-octenal, 1-octen-3-ol, Z-4-decenal, E,E-2,4-nonadienal, guaiacol, gamma-octalactone, and m-cresol. Over 20 compounds were identified for the first time in orange essence oil using MS, however, most did not exhibit aroma activity. 相似文献
937.
Jiménez JC Chavarría B López-Macià A Royo M Giralt E Albericio F 《Organic letters》2003,5(12):2115-2118
[reaction: see text] A solid-phase method for the synthesis of tentoxin has been developed. Two key steps-dehydration and N-alkylation-are carried out while the peptide is anchored to the resin. The method, which has been validated by the preparation of a library of tentoxin analogues, should be applicable to the generation of further libraries that have the tentoxin scaffold structure, as well as other structures containing N-alkylated didehydroamino acids. 相似文献
938.
Rosa Ortiz Joaquín Borrás Lourdes Perelló Horacio Jimenez 《Monatshefte für Chemie / Chemical Monthly》1986,117(4):443-451
The formation constants of the binary complexes Cu(CM)2+ and Cu(CM)
2
2+
as well as those of the ternary complexes Cu(CM)L
+ and Cu(CM)2
L
+ (CM=Cimetidine=N-Cyano-N-methyl-N[(5-methyl-1H-imidazol-4-yl)methyltioethyl]-guanidine; HL=Phenobarbital=5-ethyl-5-phenyl-barbituric acid) have been determined in 0.1 and 1.0 mol dm–3 NaClO4 methanol solutions at 25±0.2°C. The values of logX, log stat.., and logK confirm the stability of the ternary complexes.
Ternäre Komplexe von Cimetidin und Phenobarbital mit Cu(II) in methanolischer Lösung
Zusammenfassung Die Stabilitätskonstanten der binären Komplexe Cu(CM)2+ und Cu(CM) 2 2+ sowie die der ternären Komplexe Cu(CM)L + und Cu(CM)2 L + (CM=Cimetidin=N-Cyan-N-methyl-N-[(5-methyl-1H-imidazol-4-yl)methylthioethyl]-guanidin; HL=Phenobarbitalum=5-Ethyl-5-phenyl-barbitursäure) wurden in 0.1 und 1.0M Lösungen von NaClO4 in Methanol bei 25±0.2°C bestimmt. Die Werte von logX, log stat. und logK bestätigen die Stabilität der ternären Komplexe.相似文献
939.
Summary Mercury(II) in the presence of a large excess of thiocyanate forms a violet colour with Rhodamine B. The complex formed can be stabilized by addition of poly(vinyl alcohol), and forms the basis for a spectrophotometric method for determination of trace amounts of mercury. The calibration graph for measurement at 610 nm is linear in the range 1–15g of mercury per 25 ml, with a molar absorptivity of 1.1×105l· mole–1·cm·. The effect of foreign ions has been studied and the method can be applied to the determination of mercury in air with reliable analytical results.
Spektrophotometrische Bestimmung von Quecksilber mit Rhodanid und Rhodamin B
Zusammenfassung In Gegenwart eines großen Überschusses von Rhodanid bildet Hg(II) mit Rhodamin B eine violette Färbung. Durch Zusatz von Polyvinylalkohol kann dieser Komplex stabilisiert werden und bietet somit die Grundlage für die spektrophotometrische Bestimmung von Hg-Spuren. Die Eichkurve für die Messung bei 610 nm verläuft für 1–15g Hg/25 ml linear. Die molare Absorptivität beträgt 1,1×105 l·mol–1·cm–1. Die Fremdionenwirkung wurde untersucht. Das Verfahren kann zur Hg-Bestimmung in Luft verwendet werden.相似文献
940.
Palazón J. Gálvez J. García G. López G. 《Journal of Thermal Analysis and Calorimetry》1987,32(2):645-652
The preparations of the nickel-morpholine (Morph) complexes Ni(NO2)2·3Morph and Ni(ClO4)2·4Morph·2H2O are described. The thermal treatment of this perchlorate and of NiSO4·2Morph led to the isolation of Ni(ClO4)2·2Morph·2H2O and NiSO4·Morph. The magnetic moments, diffuse reflectance spectra and infrared spectra of these compounds are all compatible with a pseudo-octahedral environment around the nickel atom.
The authors are indebted to Consejeria de Cultura y Educación de la Comunidad Autónoma de Murcia for financial support. 相似文献
Zusammenfassung Die Darstellung der Nickel-Morpholin(Morph)-Komplexe Ni(NO2)2·3Morph und Ni(ClO4)2·4Morph·2H2O wird beschrieben. Die thermische Behandlung dieses Perchlorates und von NiSO4·2Morph ergibt Ni(ClO4)2·2Morph·2H2O und NiSO4Morph. Magnetisches Moment sowie diffuse Reflektionsspektren und Infrarotspektren dieser Verbindungen sind kompatibel mit einer pseudooktaedrischen Koordination des Nickelatoms.
, () : Ni(NO2)2·, NiSO4·2 Ni(ClO4)2·4·2H2O. NiSO4· Ni(ClO4)2·2·2H2O. , , .
The authors are indebted to Consejeria de Cultura y Educación de la Comunidad Autónoma de Murcia for financial support. 相似文献